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Concept: Yttrium aluminium garnet


This work presents a novel white light device. An yttrium aluminum garnet (YAG) phosphor-incorporated zinc oxide (ZnO) film is deposited on a slide glass substrate by ultrasonic spray pyrolysis. A nanoflower consisting of a hexagonal nanopetal is formed on the surfaces of the samples, and the sizes of the nanopetal are approximately 200 to 700 nm. Additionally, the nanopetal becomes blunted with an increasing incorporated amount of YAG. As the incorporated amount is 1.5 and 2.5 wt.%, the photoluminescence color of the YAG-incorporated ZnO film is nearly white, possibly contributing to the YAG emission and the band-to-deep level transition in the ZnO film.

Concepts: Aluminium, Zinc, Color, Titanium dioxide, Zinc oxide, Yttrium aluminium garnet, Garnet, Yttrium


The physics of strong-field applications requires driver laser pulses that are both energetic and extremely short. Whereas optical amplifiers, laser and parametric, boost the energy, their gain bandwidth restricts the attainable pulse duration, requiring additional nonlinear spectral broadening to enable few or even single cycle compression and a corresponding peak power increase. Here we demonstrate, in the mid-infrared wavelength range that is important for scaling the ponderomotive energy in strong-field interactions, a simple energy-efficient and scalable soliton-like pulse compression in a mm-long yttrium aluminium garnet crystal with no additional dispersion management. Sub-three-cycle pulses with >0.44 TW peak power are compressed and extracted before the onset of modulation instability and multiple filamentation as a result of a favourable interplay between strong anomalous dispersion and optical nonlinearity around the wavelength of 3.9 μm. As a manifestation of the increased peak power, we show the evidence of mid-infrared pulse filamentation in atmospheric air.

Concepts: Fundamental physics concepts, Physics, Light, Electromagnetic radiation, Laser, Frequency, Yttrium aluminium garnet, Garnet


BACKGROUND: Unwanted hair growth is a common aesthetic problem. Laser hair removal has emerged as a leading treatment option for long-term depilation. OBJECTIVES: To extensively review the literature on laser hair removal pertaining to its theoretical basis, current laser and light-based devices, and their complications. Special treatment recommendations for darker skin types were considered. MATERIALS AND METHODS: A comprehensive literature search related to the long-pulse alexandrite (755 nm), long-pulse diode (810 nm), long-pulse neodymium-doped yttrium aluminum garnet (Nd:YAG; 1,064 nm), and intense pulsed light (IPL) system, as well as newer home-use devices, was conducted. RESULTS: The literature supports the use of the alexandrite, diode, Nd:YAG and IPL devices for long-term hair removal. Because of its longer wavelength, the Nd:YAG is the best laser system to use for pigmented skin. Further research is needed regarding the safety and efficacy of home-use devices. CONCLUSION: Current in-office laser hair removal devices effectively provide a durable solution for unwanted hair removal.

Concepts: Light, Hirsutism, Yttrium aluminium garnet, Intense pulsed light, Hair removal, Laser hair removal, Depilation, Electrology


BACKGROUND: The efficacy of fractional erbium-doped yttrium aluminum garnet (Er:YAG) and carbon dioxide (CO(2) ) lasers are well substantiated. OBJECTIVE: To compare the efficacy and safety of these two laser systems for treatment of atrophic scars in dark-skinned patients. MATERIALS AND METHODS: Twenty-four subjects with acne scars were randomly treated with a fractional Er:YAG laser on one side and a fractional CO(2) laser on the other side. All subjects received two treatments with a 2-month interval. Objective and subjective assessments were obtained at baseline and 1, 3, and 6 months after the final treatment. RESULTS: At the 6 month follow up, 55% and 65% of Er: YAG and CO(2) laser sites, respectively, were graded as having more than 50% improvement of scars. Improvement progressed significantly from 1- to 6-month follow-up (p < .001). There was no significant difference in clinical improvement between the two systems at 1- (p = .90), 3- (p = .54), and 6-month (p = .87) follow-up. Reduction in scar volume corresponded to clinical evaluation. CONCLUSIONS: Fractional Er:YAG and CO(2) lasers provided comparable outcomes of scar treatment, but fractional CO(2) laser was associated with greater treatment discomfort.

Concepts: Carbon dioxide, Scar, Acne vulgaris, Erbium, Yttrium aluminium garnet, Garnet, Solid-state laser, Active laser medium


BACKGROUND: Tranexamic acid (TA) has recently gained in popularity in the treatment of pigmentary disorders. OBJECTIVE: To evaluate the clinical efficacy and safety of oral TA combined with low-fluence 1064-nm quality-switched neodymium-doped yttrium aluminum garnet (QSNY) laser for the treatment of melasma. MATERIALS AND METHODS: Forty-eight patients with melasma were enrolled in the study and subsequently divided into two groups: a combination group and a laser treatment group. All patients were treated with two sessions of low-fluence QSNY laser, and patients in the combination group took 8 weeks of oral TA. Two blinded dermatologists evaluated patients using the Modified Melasma Area and Severity Index (mMASI) and a clinical improvement scale. RESULTS: Mean mMASI score 4 weeks after the second treatment decreased significantly in both groups from base line. Based on overall clinical improvement, a greater number of patients scored as grade 3 and more in the combination group; no patients were scored as grade 4 in the laser-alone group. CONCLUSIONS: Oral TA may prove a safe and efficient treatment option for melasma in combination with low-fluence QSNY laser therapy.

Concepts: Medicine, Aluminium, Dye laser, Erbium, Yttrium aluminium garnet, Garnet, Laser hair removal


A study was designed to determine and describe the changes induced in the anterior segment of the eye and the intraocular pressure (IOP) after laser peripheral iridotomy (LPI) versus phacoemulsification in primary angle closure suspects (PACS) and primary angle closure (PAC).

Concepts: Ophthalmology, Yttrium aluminium garnet, Garnet, Yttrium


In this Letter we introduce a new class of Fano-resonant all-dielectric metasurfaces for enhanced, high figure of merit magneto-optical response. The metasurfaces are formed by an array of magneto-optical bismuth-substituted yttrium iron garnet nano-disks embedded into a low-index matrix. The strong field enhancement in the magneto-optical disks, which results in over an order of magnitude enhancement of Faraday rotation, is achieved by engineering two (electric and magnetic) resonances. It is shown that while enhancement of rotation also takes place for spectrally detuned resonances, the resonant excitation inevitably results in stronger reflection and low figure of merit of the device. We demonstrate that this can be circumvented by overlapping electric and magnetic resonances of the nanodisks, yielding a sharp electromagnetically induced transparency peak in the transmission spectrum, which is accompanied by gigantic Faraday rotation. Our results show that one can simultaneously obtain a large Faraday rotation enhancement along with almost 100% transmittance in an all-dielectric metasurface as thin as 300 nm. A simple analytical model based on coupled-mode theory is introduced to explain the effects observed in first-principle finite element method simulations.

Concepts: Scientific method, Electromagnetism, Michael Faraday, Optics, Magnetism, Engineering, Finite element method, Yttrium aluminium garnet


Transparent crystalline yttrium aluminum garnet (YAG; Y3Al5O12) is a dominant host material used in phosphors, scintillators, and solid state lasers. However, YAG single crystals and transparent ceramics face several technological limitations including complex, time-consuming, and costly synthetic approaches. Here we report facile elaboration of transparent YAG-based ceramics by pressureless nano-crystallization of Y2O3-Al2O3bulk glasses. The resulting ceramics present a nanostructuration composed of YAG nanocrystals (77 wt%) separated by small Al2O3crystalline domains (23 wt%). The hardness of these YAG-Al2O3nanoceramics is 10% higher than that of YAG single crystals. When doped by Ce3+, the YAG-Al2O3ceramics show a 87.5% quantum efficiency. The combination of these mechanical and optical properties, coupled with their simple, economical, and innovative preparation method, could drive the development of technologically relevant materials with potential applications in wide optical fields such as scintillators, lenses, gem stones, and phosphor converters in high-power white-light LED and laser diode.

Concepts: Optical fiber, Laser, Solid, Light-emitting diode, Yttrium aluminium garnet, Garnet, Yttrium, Optical materials


Rare-earth-doped laser materials show strong prospects for quantum information storage and processing, as well as for biological imaging, due to their high-Q 4f↔4f optical transitions. However, the inability to optically detect single rare-earth dopants has prevented these materials from reaching their full potential. Here we detect a single photostable Pr(3+) ion in yttrium aluminium garnet nanocrystals with high contrast photon antibunching by using optical upconversion of the excited state population of the 4f↔4f optical transition into ultraviolet fluorescence. We also demonstrate on-demand creation of Pr(3+) ions in a bulk yttrium aluminium garnet crystal by patterned ion implantation. Finally, we show generation of local nanophotonic structures and cell death due to photochemical effects caused by upconverted ultraviolet fluorescence of praseodymium-doped yttrium aluminium garnet in the surrounding environment. Our study demonstrates versatile use of rare-earth atomic-size ultraviolet emitters for nanoengineering and biotechnological applications.

Concepts: Electron, Quantum mechanics, Stimulated emission, Atom, Fluorescent lamp, Yttrium aluminium garnet, Garnet, Yttrium


The aim of this study was to examine the shear bond strength (SBS) of ceromer and nanohybrid composite to direct laser sintered (DLS) Cr-Co and Ni-Cr-based metal infrastructures treated with erbium-doped yttrium aluminum garnet (Er:YAG), neodymium-doped yttrium aluminum garnet (Nd:YAG), and potassium titanyl phosphate (KTP) laser modalities in in vitro settings.

Concepts: Calcium, Chemical element, Laser pointer, Nonlinear optics, Erbium, Yttrium aluminium garnet, Garnet, Lasers